Found an interesting article in which one guy did some datamining on some popular exchanges and their volumes:
https://medium.com/@sylvainartplayribes/chasing-fake-volume-a-crypto-plague-ea1a3c1e0b5eApparently a few of these giants are falsifying their volumes. Maybe because a higher market cap would make people think it's a more trustworthy exchange? I don't know if it's really worth going through all of that effort.
Would this have a major effect on the prices? I know we used to see huge differences in prices in the past, but now you won't see much more than a few percent here and there between exchanges.
I think it's an old practice that will persist as you all know there are so many exchanges right now and more are coming, and they are vying for traders and investors attention the more traders see volume and a lot of activities the more they get attracted to this exchanges one exchange is Yobit.